Diffusion of chemicals in polymers and composites can induce a mechanical response, causing material deformation, a decrease in the material modulus, and transition of the material to a more rubbery state. These changes in mechanical state are often related to changes in other properties, particularly in the case of functional polymers and lithium ion batteries. Additionally, current physics-based diffusion models may not account for composition-dependent mechanical properties, which can result in errors in predicting chemical permeation. In this contribution, we explore the changes in mechanical properties of both pure polyurethane and polyurethane-based composites after exposure to different chemicals using force spectroscopy (polymer) and tensile testing (composites). The functional dependence of material properties determined by these experiments are input to an adapted viscoelastic diffusion model accounting for the composition-dependent properties. Experimental chemical breakthrough curves are obtained by the use of modified ATR methods based on time-resolved FTIR spectroscopy previously demonstrated in our lab. This work provides experimental methods in addition to an adapted diffusion model which has practical applications in chemical decontamination and polymer-based separation membranes.

Concentration-dependent mechanical properties of polyurethane and polyurethane-based composites during chemical permeation

2019 Spring National Meeting

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